1. Field of the Invention
The present invention relates to an application-film transfer tool including a clutch mechanism and a reverse-rotation prevention mechanism and, more specifically, relates to an application-film transfer tool in which part of a supply bobbin constitutes part of the reverse-rotation prevention.
2. Description of the Related Art
Various application-film transfer tools that are used for applying glue or correcting characters have been proposed in the past. Such application-film transfer tools have a case accommodating a supply bobbin around which unused transfer tape is wound, a take-up bobbin that takes up used transfer tape from the supply bobbin, and interlocking means for interlocking the supply bobbin and the take-up bobbin. The transfer tape used by such an application-film transfer tool is constituted of a base tape, which is a conveying medium, made of resin tape or paper tape, and an application film that easily peels off the surface of the base tape.
With such an application-film transfer tool, the application film for the transfer tape can be transferred onto a transfer subject by extending the transfer tape around a transfer head protruding from the case, closely contacting the transfer head with the transfer subject, such as paper, and moving the case while pressing the transfer head against the transfer subject. At the same time, the transfer tape is reeled out from the supply bobbin, and the used transfer tape (base tape) is taken up by the take-up bobbin.
With such an application-film transfer tool, transfer might fail when the transfer tape sags. Therefore, the rotational speed of the take-up bobbin is set greater than the rotational speed of the supply bobbin so that tension of the transfer tape is constantly maintained above a predetermined value. As the application-film transfer tool is used, the amount of the transfer tape wound around the supply bobbin decreases, and the amount of the base tape wound around the take-up bobbin increases. Consequently, the amount of base tape taken up by one rotation of the take-up bobbin increases each time the take-up bobbin rotates. As a result, the transfer load required for application film increases, and it becomes difficult to transfer the application film. Thus, the supply bobbin is over-rotated such that the rotation of the supply bobbin is not fully transmitted to the take-up bobbin. Usually, an application-film transfer tool has a clutch mechanism that absorbs the difference in the amounts of tape conveyed by the supply bobbin and the take-up bobbin and adjusts the tension in the transfer tape.
To transfer the application film of the transfer tape onto a transfer subject using the application-film transfer tool, the case is moved. However, when the case is moved in a direction opposite to the movement for transferring the application film, the transfer tape may sag and/or may become tangled inside the case. To prevent such problems, a typical application-film transfer tool includes a reverse-rotation prevention mechanism.
For example, Japanese Unexamined Patent Application Publication No. 2002-205867 proposes an application-film transfer tool including a clutch mechanism in which resilient arms (curved members), contacting the inner circumferential surface of a supply bobbin, are cantilevered at 120° intervals along the circumference of a rotary shaft of the supply bobbin on the outer circumference of the rotary shaft and a reverse-rotation prevention mechanism having a latching arm provided on a supply-side gear and teeth, which are latching grooves, provided on the inner surface of the case.
In Japanese Unexamined Patent Application Publication No. 2003-103994, the inventor proposes an application-film transfer tool that includes an easily-replaceable clutch mechanism slidable by including a clutch member with resilient arms provided on a rotary shaft in a circular depression formed in the upper surface of a supply-side gear and contacting projections provided at the ends of the resilient arms to the inner circumferential surface of the circular depression. A reverse-rotation prevention mechanism of such an application-film transfer tool may include, for example, a ratchet gear further provided on a gear part of a take-up bobbin and a latching arm provided on a flat plate of a case in such a manner that it engages with the ratchet gear. In this way, reverse rotation of a supply bobbin can be prevented.